Improvement of the CdTe diode detectors using a guard-ring electrode

Abstract

Recent results from the Schottky CdTe diode detectors employing a guard-ring (GR) electrode are reported. A cathode electrode, made of platinum, was separated into an active electrode(s) and a surrounding GR. Typical leakage current of a device with active area of 2 /spl times/ 2 mm/sup 2/ and 0.5 mm thickness surrounded by a GR, is 7 and 20 pA at a bias of 100 and 500 V, respectively, operated at 20/spl deg/C. Spectral resolution of this device is 0.93 and 1.2 keV (FWHM) at 59.5 and 122 keV, respectively, operated at 20/spl deg/C with a bias of 800 V. Detailed study of the characteristics of these devices working as a gamma-ray detector is presented.